From 37f3cff525815b16e87f62e8e6aca9798ab75e99 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marc-Andr=C3=A9=20Moreau?= Date: Sat, 2 Jul 2011 17:10:10 -0400 Subject: [PATCH] libfreerdp-core: started TPDU encoding/decoding --- libfreerdp-core/CMakeLists.txt | 2 + libfreerdp-core/tpdu.c | 116 +++++++++++++++++++++++++++++++++ libfreerdp-core/tpdu.h | 45 +++++++++++++ libfreerdp-core/tpkt.c | 18 +++-- libfreerdp-core/tpkt.h | 5 +- 5 files changed, 176 insertions(+), 10 deletions(-) create mode 100644 libfreerdp-core/tpdu.c create mode 100644 libfreerdp-core/tpdu.h diff --git a/libfreerdp-core/CMakeLists.txt b/libfreerdp-core/CMakeLists.txt index f0060b4a8..96492be1b 100644 --- a/libfreerdp-core/CMakeLists.txt +++ b/libfreerdp-core/CMakeLists.txt @@ -30,6 +30,8 @@ set(LIBFREERDP_CORE_SRCS # credssp.h # ntlmssp.c # ntlmssp.h + tpdu.c + tpdu.h tpkt.c tpkt.h ) diff --git a/libfreerdp-core/tpdu.c b/libfreerdp-core/tpdu.c new file mode 100644 index 000000000..ea0d26694 --- /dev/null +++ b/libfreerdp-core/tpdu.c @@ -0,0 +1,116 @@ +/** + * FreeRDP: A Remote Desktop Protocol Client + * X.224 Transport Protocol Data Units (TPDUs) + * + * Copyright 2011 Marc-Andre Moreau + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "tpdu.h" + +/** + * TPDUs are defined in: + * + * http://www.itu.int/rec/T-REC-X.224-199511-I/ + * X.224: Information technology - Open Systems Interconnection - Protocol for providing the connection-mode transport service + * + * RDP uses only TPDUs of class 0, the "simple class" defined in section 8 of X.224 + * + * TPDU Header + * ____________________ byte + * | | + * | LI | 1 + * |____________________| + * | | + * | Code | 2 + * |____________________| + * | | + * | | 3 + * |_______DST-REF______| + * | | + * | | 4 + * |____________________| + * | | + * | | 5 + * |_______SRC-REF______| + * | | + * | | 6 + * |____________________| + * | | + * | Class | 7 + * |____________________| + * | ... | + */ + +uint8 +tpdu_read_header(STREAM* s, uint16 length) +{ + uint8 li; + uint8 code; + + stream_read_uint8(s, li); /* LI */ + stream_read_uint8(s, code); /* Code */ + + if (code == X224_TPDU_DATA) + { + /* EOT (1 byte) */ + stream_seek(s, 1); + } + else + { + /* DST-REF (2 bytes) */ + /* SRC-REF (2 bytes) */ + /* Class 0 (1 byte) */ + stream_seek(s, 5); + } + + return code; +} + +void +tpdu_write_header(STREAM* s, uint16 length, uint8 code) +{ + stream_write_uint8(s, length - 5); /* LI */ + stream_write_uint8(s, code); /* code */ + + if (code == X224_TPDU_DATA) + { + stream_write_uint8(s, 0x80); /* EOT */ + } + else + { + stream_write_uint16(s, 0); /* DST-REF */ + stream_write_uint16(s, 0); /* SRC-REF */ + stream_write_uint8(s, 0); /* Class 0 */ + } +} + +void +tpdu_write_connection_request(STREAM* s, uint16 length) +{ + tpdu_write_header(s, length - 5, X224_TPDU_CONNECTION_REQUEST); + /* TODO: RDP_NEG_DATA */ +} + +void +tpdu_write_disconnect_request(STREAM* s, uint16 length) +{ + tpdu_write_header(s, length - 5, X224_TPDU_DISCONNECT_REQUEST); +} + +void +tpdu_write_data(STREAM* s, uint16 length) +{ + tpdu_write_header(s, length - 5, X224_TPDU_DATA); +} diff --git a/libfreerdp-core/tpdu.h b/libfreerdp-core/tpdu.h new file mode 100644 index 000000000..253cc28b3 --- /dev/null +++ b/libfreerdp-core/tpdu.h @@ -0,0 +1,45 @@ +/** + * FreeRDP: A Remote Desktop Protocol Client + * X.224 Transport Protocol Data Units (TPDUs) + * + * Copyright 2011 Marc-Andre Moreau + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef __TPDU_H +#define __TPDU_H + +#include + +enum X224_TPDU_TYPE +{ + X224_TPDU_CONNECTION_REQUEST = 0xE0, + X224_TPDU_CONNECTION_CONFIRM = 0xD0, + X224_TPDU_DISCONNECT_REQUEST = 0x80, + X224_TPDU_DATA = 0xF0, + X224_TPDU_ERROR = 0x70 +}; + +uint8 +tpdu_read_header(STREAM* s, uint16 length); +void +tpdu_write_header(STREAM* s, uint16 length, uint8 code); +void +tpdu_write_connection_request(STREAM* s, uint16 length); +void +tpdu_write_disconnect_request(STREAM* s, uint16 length); +void +tpdu_write_data(STREAM* s, uint16 length); + +#endif /* __TPDU_H */ diff --git a/libfreerdp-core/tpkt.c b/libfreerdp-core/tpkt.c index eda4ce180..ad6bf61fd 100644 --- a/libfreerdp-core/tpkt.c +++ b/libfreerdp-core/tpkt.c @@ -1,6 +1,6 @@ /** * FreeRDP: A Remote Desktop Protocol Client - * TPKT Headers + * Transport Packets (TPKTs) * * Copyright 2011 Marc-Andre Moreau * @@ -17,10 +17,12 @@ * limitations under the License. */ +#include "tpdu.h" + #include "tpkt.h" /** - * TPKT headers are defined in: + * TPKTs are defined in: * * http://tools.ietf.org/html/rfc1006/ * RFC 1006 - ISO Transport Service on top of the TCP @@ -43,13 +45,15 @@ * | Length (LSB) | 4 * |____________________| * | | - * | TPDU | 5 - ? + * | X.224 TPDU | 5 - ? * .... + * + * A TPKT header is of fixed length 4, and the following X.224 TPDU is at least three bytes long. + * Therefore, the minimum TPKT length is 7, and the maximum TPKT length is 65535. Because the TPKT + * length includes the TPKT header (4 bytes), the maximum X.224 TPDU length is 65531. */ -#include - -int +uint16 tpkt_read_header(STREAM* s) { uint8 version; @@ -65,7 +69,7 @@ tpkt_read_header(STREAM* s) else { /* not a TPKT header */ - length = -1; + length = 0; } return length; diff --git a/libfreerdp-core/tpkt.h b/libfreerdp-core/tpkt.h index 241ab8bf6..5d744449c 100644 --- a/libfreerdp-core/tpkt.h +++ b/libfreerdp-core/tpkt.h @@ -1,6 +1,6 @@ /** * FreeRDP: A Remote Desktop Protocol Client - * TPKT Headers + * Transport Packets (TPKTs) * * Copyright 2011 Marc-Andre Moreau * @@ -22,9 +22,8 @@ #include -int +uint16 tpkt_read_header(STREAM* s); - void tpkt_write_header(STREAM* s, int length);